Field of Invention
The present invention relates to a system for providing location information using sound waves. The present invention, in particular, relates to a positioning system using sound waves, capable of providing the current location of a user in real time by using sound waves travelling in slower speed than radio waves in various indoor spaces such as department stores, shopping malls, museums, and art galleries.
Background
In general, positioning systems to provide location-based services (LBS) may be classified into a network-based scheme using RF signal information of cellular stations over a mobile communication network and a GPS type positioning scheme using a GPS receiver.
The above schemes may be suitable for outdoor spaces that have a superior environment to receive radio waves, but they are not suitable for shadow areas of satellite signals such as indoor spaces. In addition, the above schemes may require highly priced transmitter-receivers and highly priced relaying devices. Furthermore, high-energy radio waves can be harmful to human body.
Accordingly, various references including Korea Unexamined Patent Publication No. 2005-95401 have suggested various devices capable of detecting the location of a 3-D space by using the transmission time of sound waves. In other words, the distance (S=V×T) is obtained by recording the time, when the sound wave is generated, and time spent until the sound wave reaches a destination, and the location is detected through a triangulation scheme.
However, the applicability of the conventional location determination technologies using sound waves may not be useful since they are used to simply detect a 3-D space itself.
Since GPS signals do not reach various indoor spaces such as department stores, shopping malls, museums, and art galleries, it's not easy to provide information of a facility or an object based on user's location information or to offer convenient navigation, route suggestions, and search facility functions.
As shown in the case of using the strength of radio wave signals generated from radio wave signaling devices nearby, positioning systems using radio wave signals can produce a great margin of error and can be affected by many variables, which may not be practically useful in many cases.